21641910 has 16 divisors (see below), whose sum is σ = 51940656. Its totient is φ = 5771168.

The previous prime is 21641909. The next prime is 21641933. The reversal of 21641910 is 1914612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 360669 + ... + 360728.

It is an arithmetic number, because the mean of its divisors is an integer number (3246291).

Almost surely, 2^21641910 is an apocalyptic number.

21641910 is an abundant number, since it is smaller than the sum of its proper divisors (30298746).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21641910 is a wasteful number, since it uses less digits than its factorization.

21641910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721407.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21641910 is about 4652.0866286001. The cubic root of 21641910 is about 278.6753330816.

The spelling of 21641910 in words is "twenty-one million, six hundred forty-one thousand, nine hundred ten".